Hypergraphs Reveal Solution to 50-Year-Old Problem - Quanta Magazine

In 1973, Paul Erdős asked if it was possible to assemble sets of “triples” — three points on a graph — so that they abide by two seemingly incompatible rules. A new proof shows it can always be done.

In 1850, Thomas Penyngton Kirkman, a mathematician when he wasnt fulfilling his main responsibility as a vicar in the Church of England, described his schoolgirl problem: Fifteen young ladies in a sc… [+6711 chars]

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